Starting lineups aren't about egos, salaries or tenure. In most cases, they're about placing a team's best five-man unit on the court at the same time, as much as possible. Being a starter doesn't necessarily mean you're the best at your position (most of the time it does), but it helps the head coach formulate rotations throughout the game, which can set up advantageous matchups.
The Boston Celtics have had a difficult time organizing their frontcourt all season. Kevin Garnett has alternated between center and power forward in an attempt to keep his legs fresh, Brandon Bass has played inconsistently and tentatively on both ends of the court and big men like Chris Wilcox and Jason Collins have either been hurt or ineffective in limited minutes.
The one player—ironically, a rookie—who's been solid is Jared Sullinger. This season the Celtics have a plus-3.4 points per 100 possessions point differential when Sullinger is on the court, and a minus-3.5 when he’s off.
And in the last 10 games his impact has reached an absolutely ridiculous level. When he’s on the court, Boston’s point differential is a plus-11.9 (better than the league leading Oklahoma City Thunder). When he’s off, they’re a minus-14.1 (five points worse than the league worst Charlotte Bobcats); their offense is catastrophic, and their defense becomes a leaky ship.
When Sullinger, Rajon Rondo and Garnett share the court (as they’ve done for 97 minutes this season), the Celtics hold their opponents to 74.3 points per 100 possession, an elite number. Throw Paul Pierce into the equation, and lineups that feature those four are even better (73.2 in 65 minutes).
These sample sizes are small, but what isn’t so small is the time Garnett and Sullinger have shared together. In those 254 minutes, the Celtics are holding opponents to 85 points per 100 possessions. This is all damn impressive stuff.
Why is he doing so well? Mostly it's his impressive display of basketball intelligence. He's rotating on the back line like a 10-year veteran, taking charges and making the most of his relatively short stature by being where he's supposed to be at the right time, contesting shots at the rim.
Previously thought to be too slow to defend the pick-and-roll, Sullinger has already figured out how to use his wide body to corral speedy ball-handlers coming off the screen. And he's improving by the game.
In Boston's January 4 victory against Indiana, Sullinger made David West's job more difficult than most probably thought he could, sliding across the paint at the perfect time whenever West would put the ball on the floor to drive by a ball-pressuring Garnett.
In the clip above, as Lou Williams initiates a side screen-and-roll to separate himself from Rondo, Sullinger steps up nicely to contain the penetration, giving Rondo enough time to recover and eventually get the steal.
Sullinger's activity beneath the basket whenever a teammate attempts a shot (1.9 offensive rebounds per game, 3.7 per 36 minutes) has been a bright light for one of the worst offensive rebounding teams in NBA history. He's borderline without fault when establishing position before the shot goes up, and knowing how to move opposing players with his hips and backside at the exact right moment.
Sullinger is averaging a 10.6 point, 10.5 rebound double-double per 36 minutes (on top of 6.1 fouls). He's already proven his ability to give the Celtics big, productive minutes, and with Bass looking like a shell of the player he was last season, it's time to give the 20-year-old more minutes with the starters.
While questions still remain regarding who Sullinger would defend against a team like Miami or New York when they choose to stretch the floor and go small in the postseason, that bridge can be crossed when the time comes.
For now, he's the best rebounder Boston has (team leader in both offensive and total rebounding percentage), and giving him as much playing time as possible is the obvious decision. That starts by placing him in the starting lineup.